Abstract: A product sensor system for use in a refreshment center configured to sense a number of metal product containers. The sensor device can comprise a support shelf mounted in the refreshment center, which holds the product containers. One or more sensor loops are arranged on the shelf below the product containers, and an analysis circuit is connected to the sensor loops to measure the changes in inductance at the sensor loop when product containers are removed from the refreshment center. A microprocessor compares the signals from the inductance sensing circuit with values stored in memory to determine the amount of product remaining.